Fixed properly issue #10

Declaration of global variable $MAX_POINTS was missing in else
statement.
Replaced fixed variable with define

The ‘stfc_gfx’ string has been replaced by DEFAULT_GFX_PATH define.
Added BLOB/TEXT field initialization

Starting from mySQL 5.0.60 BLOB/TEXT field cannot have a default value
so they must be initialized when a new row is inserted in the DB.